US Park Police

At the very least, if you get on, you can still apply to your dream dept(s) and make a decision to stay or go when you get the call. If you're not picked up by an FD, you're still set for life regardless.

Qualifications include either prior law enforcement experience or 60 college credits, and being 37 y/o or younger at time of selection.

I will put in my worthless two cents and concur that the Park Police is a good organization with a lot of opportunities. The air unit is THE aerial search and rescue unit for much of the DC Metro Area.